Starting with polynomial:
P : 256*t^8 - 3584*t^6 + 13440*t^4 - 13440*t^2 + 1680
Extension levels are: 8 15
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Trying to find an order 15 Kronrod extension for:
P1 : 256*t^8 - 3584*t^6 + 13440*t^4 - 13440*t^2 + 1680
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : 256*t^23 - 28993664/1105*t^21 + 1218982464/1105*t^19 - 27469138592/1105*t^17 + 72832176032/221*t^15 - 587557652304/221*t^13 + 222176447976/17*t^11 - 649351429188/17*t^9 + 1069116542109/17*t^7 - 1796386301325/34*t^5 + 1274070981645/68*t^3 - 242579663865/136*t
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Computing nodes and weights
  current precision for roots: 53
  current precision for roots: 106
 current precision for weights: 53
Linear system for weights solvable: 0
  current precision for roots: 106
  current precision for roots: 212
 current precision for weights: 106
Linear system for weights solvable: 1
  current precision for roots: 212
  current precision for roots: 424
 current precision for weights: 212
Linear system for weights solvable: 1
Sufficient bits for target precision reached
-------------------------------------------------
The nodes are:
| (-2.4392294062913502614 + 4.9372701247834496518e-438j)  +/-  (8.62e-123, 8.62e-123j)
| (-1.5570556684172768963 - 1.4589024019358337827e-441j)  +/-  (9.55e-124, 9.55e-124j)
| (4.6688037145930793329 - 9.263504090770534875e-440j)  +/-  (1.13e-122, 1.13e-122j)
| (5.4343505708060434219 + 1.3910768932392779857e-444j)  +/-  (2.36e-123, 2.36e-123j)
| (-4.6688037145930793329 - 6.0538470572132446925e-445j)  +/-  (1.06e-122, 1.06e-122j)
| (-5.4343505708060434219 - 1.6393600548156058691e-451j)  +/-  (2.37e-123, 2.37e-123j)
| (3.4580985990147122647 - 1.1496202604488262617e-456j)  +/-  (2.31e-122, 2.31e-122j)
| (-1.1571937124467801947 + 1.5947102778331774093e-462j)  +/-  (2e-124, 2e-124j)
| (-2.9306374202572440192 + 4.1069943023702436019e-465j)  +/-  (1.94e-122, 1.94e-122j)
| (0.38118699020732211685 - 4.9458023872474031815e-469j)  +/-  (2.09e-126, 2.09e-126j)
| (1.1571937124467801947 - 1.4095536803655099067e-468j)  +/-  (1.78e-124, 1.78e-124j)
| (4.0303035109798464675 + 7.5949943886196694365e-471j)  +/-  (2.21e-122, 2.21e-122j)
| (-4.0303035109798464675 + 2.3974024006300870403e-474j)  +/-  (2.12e-122, 2.12e-122j)
| (-0.38118699020732211685 + 5.1203049867922828162e-484j)  +/-  (2.09e-126, 2.09e-126j)
| (-3.4580985990147122647 - 1.7676445912580929589e-480j)  +/-  (2.36e-122, 2.36e-122j)
| (1.9816567566958429259 + 1.6510581294542676025e-483j)  +/-  (3.13e-123, 3.13e-123j)
| (0.76721647645086548411 - 6.1979738500980433339e-492j)  +/-  (2.31e-125, 2.31e-125j)
| (9.4511150791165066533e-496 + 1.511928713449153178e-495j)  +/-  (4.1e-494, 4.1e-494j)
| (-0.76721647645086548411 - 9.8057878362731007365e-493j)  +/-  (2.31e-125, 2.31e-125j)
| (-1.9816567566958429259 + 1.6282465956033143544e-491j)  +/-  (3.36e-123, 3.36e-123j)
| (2.9306374202572440192 - 3.5796878672183418595e-492j)  +/-  (1.86e-122, 1.86e-122j)
| (1.5570556684172768963 - 3.1419671037611508274e-498j)  +/-  (9.07e-124, 9.07e-124j)
| (2.4392294062913502614 + 3.883593528017127616e-505j)  +/-  (8.08e-123, 8.08e-123j)
-------------------------------------------------
The weights are:
| (0.00069766587596080276026 + 1.2297912507839271869e-440j)  +/-  (3e-42, 1.74e-102j)
| (0.020472389386045783163 + 5.8219537677215269532e-440j)  +/-  (1.99e-38, 1.15e-98j)
| (1.3204411234998099479e-10 + 2.8730530869284735272e-446j)  +/-  (5.15e-49, 2.98e-109j)
| (7.4215619726477663232e-14 - 3.7001408346528605793e-448j)  +/-  (1.8e-50, 1.04e-110j)
| (1.3204411234998099479e-10 - 9.1406626329401625398e-446j)  +/-  (9.9e-50, 5.73e-110j)
| (7.4215619726477663232e-14 + 9.7347738097215603103e-448j)  +/-  (2.48e-51, 1.43e-111j)
| (1.9789333343661741194e-06 + 1.1065898639681804438e-443j)  +/-  (3.14e-48, 1.82e-108j)
| (0.058071460617050659648 - 9.6856892013774518205e-440j)  +/-  (1.36e-40, 7.87e-101j)
| (5.343793164142848145e-05 + 1.1435808572402464152e-441j)  +/-  (2.89e-46, 1.67e-106j)
| (0.18708734136102960663 - 1.1529478079728389178e-439j)  +/-  (1.93e-41, 1.12e-101j)
| (0.058071460617050659648 - 3.4566540886778708762e-440j)  +/-  (2.49e-42, 1.44e-102j)
| (2.9869990507723361737e-08 - 7.6402041026192475601e-445j)  +/-  (2.47e-49, 1.43e-109j)
| (2.9869990507723361737e-08 + 3.1056211062565824859e-444j)  +/-  (3.68e-49, 2.13e-109j)
| (0.18708734136102960663 - 1.5797469882777584091e-439j)  +/-  (3.09e-43, 1.79e-103j)
| (1.9789333343661741194e-06 - 6.4055257231700424208e-443j)  +/-  (5.33e-48, 3.09e-108j)
| (0.0048984195621685112186 - 3.5143178644238759709e-441j)  +/-  (3.31e-47, 1.92e-107j)
| (0.12155267067381994966 + 7.0876128651041193758e-440j)  +/-  (4.97e-44, 2.89e-104j)
| (0.21432921131368011315 + 1.5039819547682470189e-439j)  +/-  (5.42e-44, 3.15e-104j)
| (0.12155267067381994966 + 1.3585783841704627539e-439j)  +/-  (3.01e-44, 1.74e-104j)
| (0.0048984195621685112186 - 3.3996651481051653115e-440j)  +/-  (4.49e-46, 2.6e-106j)
| (5.343793164142848145e-05 - 1.0462034829078234974e-442j)  +/-  (3.13e-49, 1.82e-109j)
| (0.020472389386045783163 + 1.2860349903794466494e-440j)  +/-  (3.04e-47, 1.85e-107j)
| (0.00069766587596080276026 + 7.0566855890603232456e-442j)  +/-  (1.45e-48, 8.31e-109j)
